Hmm... other than some issues with disappearing completion windows (probably related to me running XMonad), I haven't really found it to be that ugly on linux... Maybe not very slick, but frankly speaking, for the benefits it's small price :D
Well, yeah, it's workable, but coming from IDEA on Mac it's really distractingly poor. Doesn't seem to matter what settings I tweak or fonts I use--Swing on Linux is just no fun.